<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <!--百分比是相对于父元素的-->
    <table border="1" width="50" height="50" cellpadding="5" cellspacing="2"
    align="center" bordercolor="red" bgcolor="green">
        <tr>
            <td>1</td>
            <td>2</td>
        </tr>
        <tr>
            <td>3</td>
            <td>4</td>
        </tr>
    </table>
    
    <table border="1" width="10">
        <tr bgcolor="red" height="20" align="center" >
            <td>1</td>
            <td>2</td>
        </tr>
        <tr valign="bottom" height="20" >
            <td bgcolor="red" valign="top" align="center"=>3</td>
            <td>4</td>
        </tr>
        <!--valign(垂直位置)top顶部 middle中间 bottom 下面  -->
    </table>
    <br><br><br><br>
    <table border="1" cellspacing="1" width="200" height="200">
        <tr>
            <td>不毛</td>
            <td colspan="2" rowspan="2">魏国</td>
            <!-- <td>辽东</td> -->
        </tr>
        <tr>
            <td rowspan="2">蜀国</td>
            <!-- <td>西凉</td>
            <td>幽州</td> -->
        </tr>
        <tr>
            <!-- <td>南中</td> -->
            <td colspan="2">吴国</td>
            <!-- <td>荆州</td> -->
        </tr>
    </table>
</body>
</html>